Lubricant



Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE v nunmcan'r Ulric B.Bray, Palos Verdes Estates, Calif asaignor to Union Oil Company ofCalifornia. Los Angeles, Calif., a corporation of California NoDrawing.- Application November 2, 1937,

Serial N0. 172,371

37 Claim.

ness and stabilizing constituents capable of imparting extreme pressurecharacteristics and also general insufliciently soluble in lubricatingoil at of overcoming the deposition of soot, gums, resins andvarnish-like materials upon and about the valves and rings of internalcombustion engines, and of preventing the sticking of rings and valvesespecially in engines of the Diesel type where operating conditions arein general rather severe, and also in high output aviation engines. Thisis a continuation in part of my copending application, Serial No.121,167.

In the case of many lubricating oils there has in the past been a strongtendency toward the development of resinous and similar deposits aboutvalves and rings of internal Eombustion engines due principally to thelubricating oil used, although in part to the fuel in some instances.These objectionable deposits, which often result in such sticking ofvalves and rings as to interfere materially with engine operation, areperhaps more often found in the case of Diesel engines and enginesoperating under similar severe conditions.

' I have found that the tendency of mineral lubricating oils to depositgums, resins, soot and varnish-like materials can be largely overcome bythe addition of comparatively small proportions of certain types ofmaterials which have detergent properties when dissolved or dispersed inmineral lubricating oils. By detergency I mean not only that propertywhich aids in lifting or removing, purging or washing away foreignmaterials which accumulate on the surfacesof valves, rings, pistons orother engine parts, but also that property which prevents theaccumulation or deposition of such materials, as distinguished fromsolvent action upon those accumulations or deposits.

PRELIMINARY Soaps.--The compositions suitable for this purpose belong tothe class of compounds known as oil-soluble soaps. It is preferred toemploy an oil-soluble soap having extremely high detergent power. At thesame time such oil-soluble soaps must be stable, must not polymerizeunder conditions of use and storage, and must exhibit a permanent stateof solubility or dispersion in the lubricating oil. The soaps ofunsaturated fatty acids such as calcium oleate are commonly known to besoluble in mineral oil, but these soaps of 1 unsaturated acids areunstable under engine operating conditions and produce sludge bypolymerization or oxidation. The soaps of saturated fatty acids, such ascalcium stearate are relatively more stable toward oxidation and heat,but such soaps of saturated fatty acids are in 5 atmospherictemperatures for their solutions to show suflicient detergentproperties. It, is possible to obtain temporary super-saturatedsolutions or dispersions of calcium stearate in lubricating oilhavingsufllcient soap content to exhibit satisfactory detergent propertiesunder engine operating conditions, but such super-saturated dispersionsare apt to gel, cloud or stratify during storage, thereby making suchsuspensions practically of no value in commercial operations.

Soap-solubility in mineral lubricating oils.-I have found that saturatedfatty acids, such as stearic and palmitic acids which are solids atnormal temperatures and relatively insoluble in mineral oils at ordinarytemperatures, can be converted into a liquid state at normaltemperatures which permits practically unlimited solubility of the acidsin the oils at ordinary temperature, by the expedient of chlorination ofsuch otherwise high melting point and oil-insoluble fatty acids. Forexample stearic acid which has a melting point of about 160 F. ceases tobe a solid at ordinary temperatures and becomes liquid when as little astwo chlorines are introduced into the molecule, thereby producingdichlorostearic acid which corresponds theoretically to 20.1% chlorine.The indicated soaps of such acids also are readily soluble ordispersible in mineral lubricating oils. I may sometimes use otherhalogens, 3? such as fluorine, bromine or iodine, but in general Iprefer to use chlorine. However, it is to be understood that myinvention is not limited necessarily to any particular halogen.

Besides the soaps above indicated, other appropriate oil-solublehalogenated fatty acid soaps and halogenated synthetic petroleum acidsoaps may be employed. Soaps of normally solid unsaturated fatty acids,such as elaidic acid, when chlorinated are useful, because of bothlowered melting point and stabilization by reason of the saturationproduced by the entry of chlorine at the double bond. Likewise soaps ofnormally liquid unsaturated fatty acids, such as oleic acid, whenchlorinated become valuable because the consequent saturation withchlorine at the double bond stabilizes them by overcoming susceptibilityto oxidation and polymerization. The synthetic petroleum acid soaps arethose from such acids as are produced by oxidation of petroleumfractions are likewise readily oil-soluble.

to yield oil-soluble synthetic acids of fairly high molecular weight.These synthetic petroleum acids are neither fatty acids nor naphthenicacids, and usually carry ketone, aldehyde, and/or hydroxy groups inaddition to the acid carboxyl groups.

Suitable oil-soluble soaps of these various chlorinated acids preferablyare soaps of alkaline earth metals and heavy metals in general, for ex-STATEMENT OF INVENTION Broadly stated, the invention resides in alubricating oil otherwise possessing the properties of forming sooty,gummy, resinous and varnishlike deposits upon and about valves andpiston rings of internal combustion engines, especially Diesel engines,where said lubricating oil contains a small quantity, but sufficienthowever to avoid substantial deposits of such objectionable materials,of an oil-soluble metal soap of acids of the type of halogenatedsaturated and unsaturated fatty acids and halogenated syntheticpetroleum acids of relatively high molecular weight, 1. e., having notless than about ten carbon atoms, and preferably fourteen or more carbonatoms, to the molecule. For these purposes the soaps are to be employedin the oil to the extent of about 1% to 2%, for the reason thatsubstantially greater amounts of soaps tend ordinarily to thicken theoils undesirably and to form excessive amounts of ash in the combustionchamber resulting in high rates of wear of the top piston ring and heavyash deposits on the cylinder head and exhaust valves, whereasconsiderably smaller quantities, for example about 4% or less,ordinarily do not impart sufficient stabilizing capacity to avoid orovercome deposition of gums, resins and the like. These oils alsopossess improved fllm-strength or load-carrying capacity. The inventionresides further in oil containing such soaps as above indicated for theindicated purpose wherein the oil itself is especially adapted to thesevere uses encountered in Diesel engines and the like. Such an oilpreferably is a naphthenic base oil which in itself aifords some solventcharacteristics for gums, resins, and varnishes. On the other hand,highly refined or highly paraflinic oils may be employed at least forsome uses and/or with certain of the soaps such as the calcium soap ofchlorinated synthetic petroleum acids produced by oxidation of paraffin,petrolatum or paraflinic raffinates.

Not only are the mentioned chloro-acids readily oil-soluble but thecalcium soaps therefrom While more than two chlorine atoms may beintroduced into each molecule both as to saturated and unsaturatedacids, I have found that in general two chlorine atoms are sufficient toreduce the melting point of the acids to permit adequate solubility ofboth the acids and their appropriate soaps, par-. ticularly calciumsoaps, in mineral lubricating oil. In the case of the unsaturated acidsthis chlorination effects the further desirable elimination of thedouble bond, thereby overcoming objectionable effects of theunsaturation such as susceptibility to oxidation and polymerization. Onthe basis of these acids, the chlorine content may therefore beconsidered as ranging between approximately 15% and 25% according to thesaturated, with a chlorine content which corresponds approximately todichloro-acids or somewhat less, and in general is between about 15% and25% ofchlorine based on the acid, or about 20%. The inventionparticularly applies where such soaps are calcium soaps, but may beextended also to aluminum and other equivalent soaps as indicatedherein. More broadly the invention also resides in the use of suchchlorinated material containing from 10% to 40% chlorine.

My invention also includes other various novel features, uses,combinations, proportions, compositions and methods herein disclosed,such as the use in the indicated types of lubricating oils of mixturesof calcium chlorostearates with other soaps such as calcium phenylstearate or with additional oiliness agents, corrosion inhibitors,stabilizing agents and solubilizing agents such as esters of fatty acidsor synthetic petroleum acids, amines, alcohols and ethers. The inventionmay also include sulfurized or phosphorized fatty acid or other organicacid soaps herein disclosed as substitutes for the chlorinated soapsherein disclosed.

or organic base soaps of non-halogenated acids of the types abovedescribed may be combined as one component of a doublewomponent additionmaterial with any type of oiliness or film strength agent as a secondcomponent. Such a second constituent may be methyl alpha alphadichlorstearate, other oiliness agents of the same type produced fromother alcohols such as ethyl and amyl alcohols and other chloro-acidssuch as chloro-phenyl stearic, chloro-oleic, chloropalmitic and similaracids; chlorinated naphthalene; chlorinated paraffinysulfurized orchlorinated lard oil or sperm oil or jojoba oil; chlorinated diphenyloxide; esters of synthetic petroleum acids; esters of chlorinatedsynthetic petroleum acids; tricresyl phosphate, and in general all othertypes of oiliness or film-strength-improving agents or mixtures thereof.

Therefore the invention may also be stated as extending to the use inmineral lubricating oils of an oil-soluble soap constituent combinedwith an oiliness or film-strength-improving element or constituent, suchas one or more sulfur or chlorine atoms or phosphorous groups and thelike, contained either in the soap itself, and/or contained in a secondadditive component.

In this respect, the invention also includes soaps made with organicbases such as triethanolamine, quinoline, nitrogen bases from petroleum,and the like. Such organic base soaps-may be used as substitutes forsaid oil-soluble metal soap when that soap is not chlorinated and isrequired to be used in a two-component additive material. When such anorganic base soap is aasasce chlorinated it may be used we substitutefor the oil-soluble metal chlorinated soaps either as a single componentadditive or in conjunction with other additive agents. Soaps appropriatefor this purpose are represented by triethanolamine naphthenate,trlethanolamine chloro-naphthenate, triethanclamlne chlorinated fattyacid soaps and other similar soaps of acids herein mentioned.

Usually, however, the organic base soaps are not used except in smallproportion in conjunction with metal soaps, for example, 1% of calciumdichlorostearatewith 0.3% of triethanolamine dicbiorostearate;

The invention also includes reneutralization, as oil-soap concentrate orblended oil wherethe acid number is too high, to reduce to a maximumacid number, such as 0.2, by the use of more of the original base or theaddition of another base, and in the latter connection, the abovementioned organic bases such as triethanolamine are valuable and resultin a mixture of soaps.

The invention also resides in oil-soap concentrates herein described, aswell as in the finally blended oils, especially as such concentrates aresubstantially completely dehydrated and are therefore fluid at normaltemperatures and readily miscible with lubricating oil, especially ofthe n'aphthenic type.

While I do not wish to be limited by theory, the following explanationwill aid in understanding my invention. A stable oil-soluble soap ofhigh detergent power is effective in preventing ring sticking, and alsoincreases the oiliness" of the compounded oil to give improvedlubrication under light or mild service conditions over straight mineraloil. due to preferential adsorption of the carboxyl group of the organicacid radical of the soap on the metal surfaces. As the temperature andpressure increase under heavier loading and higher power output, theadsorbed layer of soap or acid constituent thereof breaks down,permitting metal to metal contact resulting in a scuifing, galling,scratching, and eventual failure of the engine. Under these severeconditions, the high film strength element essential to my inventioncomes into play and prevents disruption of the lubricating film. Thehigh temperature apparently activates the film strength element,chlorine for example, causing it to displace the more mild oilinessagent of the soap or organic acid type in the adsorbed layer. The rateof apparent wear is probably greater when chlorine or liberated HCl isresponsible for the adsorbed layer, and, while a higher rate of wear ispreferable to complete failure in emergencies, it is therefore betternot to have the active chlorine type of adsorbed layer in effect at allother times. In the compositions shown herein, there is provided inaddition to the active film strength agent such as chlorine, anoxygenated type of oiliness agent in the form of the carboxyl group of asoap, ester, or free fatty acid or ketone, aldehyde, ether or alcoholradical; said oxygenated agents being intended to provide the adsorbedlubricating layer and displace the high film'strength agent therefromunder ordinary operating conditions. Thus an outstanding feature of myinvention consists in providing in acompounded lubricating oil anoiliness agent of the oxygenated type for use under normal operatingconditions and a higher film strength agent which becomes active andrescues the lubricating film under emergency conditions. Insofar asspecific soaps herein disclosed are new in lubricants, the

invention also extends to the use of such soaps in lubricating oils insufilcient quantities and with necessary hydration to produce greaseshaving severe service characteristics similar to those of thelubricating oils described.

Dascarrrros m Daren.

In practicing the present invention, any othersatisfactory minerallubricating oil is selected. As above indicated, this is preferably anaphthenic base or Western type oil, especially where such an oil is tobe used for Diesel engine lubricating oil. On the other hand withchlorinated synthetic petroleum acid soaps, for example, I have employedsuccessfully paramnic The soaps which I have found to be highlysatisfactory for these purposes are especially the alkali earth metalsoaps of halogenated fatty acids and of halogenated high molecularweight synthetic petroleum acids. In general such halogenated materialsare the chlorinated materials. For example the calcium soap ofchicrinated stearic acid has been found highly efficient. Similarly, thecalcium soap of chlorinated oleic acid is very desirable. calciumdichlcrostearate and the calcium dichloro-oleate function adequately inthe proportions above indicated to yield a highly satisfac tory oil forDiesel engine or similar uses, the performance of the two oils beingmuch the same, although the two chlorine atoms are presumed to beattached to the 9th and 10th carbon by direct-addition in the case ofthe chlorinated oleic acid, whereas in the case of the saturated stearicacid the two chlorine atoms are attached by substitution to the alphaand/or some other carbon probably close to the carboxyl group. Similarvpositions may be assumed in the case of the synthetic petroleum acids.

In thecase of chlorinated stearic acid, I have found that whereascalcium stearate cannot be used alone on account of lack of oilcompatibility, a substantial amount of calcium stearate can be employedwhen a larger quantity of calcium dichlorostearate is present. In otherwords, the soluble calcium chlorostearate soaps have a solubilizingaction on unchlorinated calcium stearates.

Chlorine content-While the chlorine content of the halogenated acidsused may range from 10% to 40%, for the sake of simplicity I may refergenerally to a chlorine content of about to corresponding roughly to twochlorine atoms introduced into the acid molecule. as being typical of myinvention; for example, dichloro-stearic acid and dichloro-oleic acid.Apparently mixtures are obtained containing y from 1 to 3 or 4 or evenmore chlorine atoms per molecule, and in using these materials it issatisfactory to use products containing from about 17% to 21% or evenwithin a range sometimes of 15% to 25% or the above men- Both the tionedwider range of 10% to 40% chlorine being also within the scope of theinvention.

The introduction of only one chlorine atom causes apparently a markedlowering in the melting point of the normally solid acids such asstearic acid, but the introduction of two chlorines per molecule yieldsan acid thoroughly liquid at temperatures as low as 20 F. in the case ofstearic acid. The mono-chlor derivative of stearic acid corresponds to achlorine content of 11.2% while the dichlor derivative corresponds to achlorine content of 20.1%. The chlorination may be continued toincorporate more than two chlorine atoms in each molecule of the acid ifdesired, the trichior-clerivative of stearic acid having 27.4% chlorine,but I have found that two chlorine atoms generally are sufficient toreduce the melting point to the desired degree and to improve thesolubility of the acid and its soaps in mineral lubricating oil to thepoint where it may be used m practicing my invention. Usually a mixtureis obtained on chlorination containing unchlorinated acid as well asacids carrying one, two or more chlorine atoms per molecule. Thus,

chlorinating any particular acid to achieve a pre-- determined chlorinecontent corresponding to a theoretical dichloro-acid (i. e.'20.1%chlorine in the case of stearic acid) does not give a material which ispure dlchloro-acid. To study the behavior of the pure acids, thechloro-products must be resolved into the various species. However, inpractical operations it has been found possible to use the overallchlorine content as a guide in obtaining suitable materials forpracticing my invention.

Unsaturated fatty acids which also are solid at normal temperatures,such as elaidic acid, can be converted into lower melting point acids bythe simple addition of chlorine at the double bond of the hydrocarbonchain. Liquid unsaturated fatty acids, such as oleic acids, are improvedby chlorination, not so much .as regards melting point and solubility inmineral oil, but as regards susceptibility to oxidize and polymerize atengine temperatures by reason of the elimination of the double bonds atwhich the chlorine enters as in the case of the two chlorine atoms indichlorooleic acid.

Chlorinated soaps.When I have reduced the melting point of the normallysolid fatty acids by chlorination sufficiently to achieve miscibility ofthe fatty acids with lubricating oil at ordinary temperatures, I findthat the calcium soaps of such chlorinated fatty acids are also solublein the lubricating oil to a greater extent than the calcium soaps of thecorresponding nonchlorinated fatty acids. Thus, by chlorinating fattyacids I am able to produce synthetic acids which yield soaps of greatlyimproved solubility in mineral lubricating oils. Also, when I useunsaturated fatty acids as raw materials, I produce synthetic acidshaving no unsaturated double bonds and thereby correct the abnormaloxidizing and polymerizing tendency of the orig- Thus by chlorination Ican eating oils.

produced therefrom with the mineral lubricating oil to be employed. As afurther feature of my invention, the chlorinated soaps are not onlysoluble themselves in oil, but have the property of increasing the oilsolubility or compatibility of otherwise relatively insoluble orincompatible unchlorlnated soaps. This makes it unnecessary to removeall of the unchlorinated acids from the reaction products obtained uponchlorinating, say, stearic acid.

I have found that, as a general practice, soaps which are'most readilycompatible with mineral oils are produced from acids which are misciblewith lubricating oil in all proportions. However it is not true that allacids which are miscile with lubricatingoils will necessarily yieldsoaps which are compatible with or soluble in such lubricating oils. Anotable example of such an insolublesoap is found in the case of thesoaps of the low melting point saturated acids from cocoanut atoms, andyield soaps readily soluble or compatible with mineral lubricating oils,of which 'naphthenic base oils are desirable examples.

For the purpose of obtaining the increased film strength which I havediscovered necessary, I may chlorinate such liquid acids as phenylstearic acid which already yield oil-soluble calcium soaps.

Position and number of chlorine atoms.--As has been indicated above,experimental research makes it appear that the exact location of thechlorine atoms is not critical. For example, chlorination of theunsaturated oleic acid with two chlorines will result in the simpleaddition of the two chlorine atoms at the double bond, that istheoretically on the 9th and 10th carbon atoms in the chain. On theother hand, chlorination to introduce two chlorine atoms into saturatedacids such as stearic or palmitic acid will theoretically cause thechlorines to enter close to the COOH group. It is probable that in mostinstances the two chlo'rines will enter on the alpha carbon bysubstitution for the hydrogens, but it is possible that they might enteron the beta carbon or on the gamma or on any other carbon, or on twodifferent carbons, or on different carbons in different molecules. Forthe sake of this description, it may be convenient to assume that bothchlorine atoms enter on the alpha car'- bon without, however,restricting me to any such theory.

Film strength-I find that chlorination of fatty acidsnot only yieldscalcium soaps sufiiciently soluble in mineral oil to give the requireddetergent action to prevent ring sticking, but the presence of chlorinealso imparts improved oiliness and film strength to finished compoundedlubri- As an example, an acid treated naphthene base oil of 21.0 A. P.I. gravity at 60 F. and 54 seconds Saybolt Universal viscosity at 210 F.was found to carry a maximum load of only pounds on a 'Iimken filmstrength testing machine. but when compounded with 1.3% of calciumdichlorostearate the same oil carried a load of 35 pounds on the Tlmkenmachine. The film strength on the Almen machine was raised from 6 poundsto 12 pounds, and on the S. A. E. machine from 60 pounds to 440 poundsat 250 it P. M., rubbing ratio 14.6 to 1, and a loading rate of 75pounds per second. (For descriptions of these machines, see S. A. EJournal, vol. 28, 1931, pages 53 to 60, and vol. 39, 1936, pages 293 to296.)

In actual Diesel engine operation, it was determined that in aparticular engine, the non-compounded oil could be used only up to 90pounds per square inch brake-mean-efiective pressure loading of theengine without scuillng rings and cylinder wall, whereas aftercompounding with the 1.3% calcium dichlorostearate, the oil was able tocarry a loading of 106 pounds brakemean-eiiective pressure which is themaximum power that could be developed by the engine withoutsupercharging. Under the severe conditions of overloading in comparisonwith the normal operating brake-mean-eil'ective pressure of 75 poundsper square inch, perfect lubrication was obtained with the compoundedoil.

In break-in tests on engines fitted with new liners, pistons and rings,it has been found that, with the compounded 011 containing calciumchlorostearate, full normal operating load can be safely applied afteronly one hour of running-in, as compared with a customary 15 to 18 hourrunning-in period. Furthermore, after 100 hours of normal full loadoperation the surfaces of the liners and ring faces are in materiallybetter wearing condition when the compounded oil is used after only aone hour break-in period, than when the uncompounded oil is used after aseventeen hour break-in period with the uncompounded oil. The betterrunning-in and wearing properties of the compounded lubricant are shownin the wear figures obtained in carefully controlled tests runcontinuously at normal full load; the cylinder wear being 0.0004 inchper 1000 hours for the non-compounded oil and only 0.0008 inch per 1000hours for the compounded oil.

The compounded oil containing an oiliness component of the oxygenatedtype and a high film strength agent for emergency conditions should showa minimum fllm strength of 15 lbs. on the Timken machine or 9 lbs. onthe Almen machine.

Paon'uc'non or CHLoRo Acrus ghlorostearic acids.--As a convenient meansfor practicing the invention, soaps of the chlorostearic acids,particularly the calcium soaps, will be considered without howeverindicating any exclusion of the other chloro-organic acids and theirsoaps herein mentioned. While I have referred above to a simplechlorination of the various acids by bubbling free chlorine through theacids in liquid or melted condition, it will be apparent that othermeans may be employed, such as treating the alkali soap solution ofunsaturated acid (e. g. sodium oleate) with hypochlorite, or dissolvingoleic acid in a solution of sodium hypochlorite.

Direct chlorinati0n.-Direct chlorination of the saturated acids may beeffected in liquid or melted form directly by bubbling chlorinetherethrough at temperatures of 175 F. to 240 1". in the absence of anydiluent or the like. Preferably the temperature is controlled to notover 220 F. during chlorination. Again chlorination may be eifected bybubbling chlorine through a be effected by fractional crystallizationwhere it is desired to remove unchlorinated or insufficientlychlorinated acids. Or when the material is chlorinated in the presenceof a diluent such as carbon tetrachloride, the desired chlorinated acidsmay be separated by cooling to the desired degree, e. 3., 0 F. andsimply cold pressing; or chlorinated materials can be diluted, cooledand cold pressed, whereby the materials crystallized I at the respectivetemperature are recovered on the filter. chlorinated (mono chloro) acidsseparated on the filter may be recycled to the chlorination process ifdesired.

Where a diluent is used in chlorinating, after The unchlorinated or onlypartially sufllcient chlorination the flow of the chlorine is stoppedand the mixture is blown with a neutral gas such as flue gas or C0: ornatural gas or nitrogen or subjected to vacuum for the purpose ofremoving the free chlorine and dissolved hydrochloric acid; the mixtureis then cooled, and filtered or settled or centrifuged; and then thematerials are heated for the recovery of the solvent or diluent.Necessarily, high temperatures must be avoided to prevent liberation ofhydrochloric acid. Fractional crystallization is preferred asdistinguished from fractionation by distillation on account ofdecomposition and splitting out of HCl when attempting fractionaldistillation.

Preparation from chlorinated esters.-As an- 40 other means of obtainingthe chlorostearic acids, stearic acid may be reacted with methyl alcoholto produce methyl stearate and this material treated with chlorine toyield methyl-chlorostearates which when saponified with sodium hydroxidesolution yield sodium chlorostearates. Dlchlorostearic acids (and otherchloro-acids as the case may be) are then obtained by acidifying theaqueous soap solution with sulfuric acid.

The dichlorostearic acids are then washed and' separated. To facilitatewashing and separation, an extract may be obtained from an aqueoussolution by means of a low boiling solvent (e. g. petroleum naphtha)having selective solvent properties for the chlorostearic acids. As analternative, I may extract the aqueous mixture with a portion of thelubricating oil eventually to be used. In this event the lubricating oilsolution is decanted and allowed to stand at 175 F. to 200 F. untilpractically all of the waas a low iodine number on the chlorinated prod-7 Considering the production of soaps of chlorofatty acids of thisinvention, the method of manufacture here also will be indicated withrespect to calcium soaps of the chlorostearic acids, which may beproduced either by direct neutralization or by double decomposition ofwatersoluble soaps.

Direct neutTaZizatin.-In preparing the soaps by direct neutralization,either a concentrate may be first produced for eventual blending with anoil or the blended oil may be obtained directly in one operation. Ineither case neutralization is effected with calcium oxide or hydroxide,preferably the hydroxide which has a more extended form, such materialspreferably being employed as a fine powder.

In producing the concentrate the required amount of chlorinated acid issimply dissolved in lubricating oil and the powdered calcium oxide orhydroxide added in an amount equivalent to, slightly less than orgreater than that required to neutralize the acids. The addition of asmall amount of water (20% to 100% of the 25 weight of the lime) appearsto aid in the neutralization. This mixture is stirred and heated toanelevated temperature, preferably to about 325 F. to 350 F. althoughlower temperatures can sometimes be used, especially where the mixtureis subjected to vacuum which aids in removing water after theneutralization is com pieted. This heating is suflicient to insurecomplete reaction between the alkali and the acids, and to remove Waterwhich would otherwise cause clouding or gelling on cooling, and tootherwise stabilize the mixture. It is desirable to use very pure limewhere stearic acids are being employed, the presence of magnesium in thelime being highly objectionable from a clouding standpoint. It has beenfound preferable to use an excess of lime, particularly when the soapconcentration is not too high, and subsequently to heat with agitationto effect neu- 5 tralization'and dehydration and to filter or centrifugeto remove excessive lime or other solid materials. The addition of 0.25%to 1.0% of a refined diatomaceous earth (such as that known I on themarket as super-eel") before or during 50 dehydration aids in filteringthe concentrate.

The production of concentrate is usually carried out in batch.

Dehydration.1t is essential to dehydrate the soap thoroughly, and I havefound that this 55 may be accomplished by heating the concentrate orsolution with agitation at 325 F. or higher up to a maximum of about 380F. until all foaming has ceased and the foam is broken.

Before this condition is reached, a thickening 60 or gelling is usuallyexperienced and a sample drawn from the kettle and cooled will set to astiff gel. When the heating and agitation have been continuedsuiiiciently to effect the desired degree of dehydration, a sample drawnfrom the 65 kettle will remain fluid though viscous on cooling withagitation. The foregoing criteria are used in determining when the batchis ready for clarification as by filtering first through a Sweetlandtype filter and then through a blotter press. To aid in maintaining afluid condition after it has cooled, the filtered concentrate may beagitated or worked" during or after cooling. The concentrate should bestored out of contact with moisture because of the hygro- 75 scopicnature of the soaps. Dehydration is to.

be as complete as possible and the water content preferably is less thanabout 0.25%.

In dehydrating the soap concentrate, it is usually preferable to use thehighest temperature convenient, taking care to avoid the access of air,but if the temperature is carried too high, as for example in excess of360 F. in the case of concentrated mixtures of calcium dichlorostearate,undesirable decomposition or polymerization reactions begin to occur.The tendency toward decomposition appears to be greater with the moreconcentrated mixtures.

By this procedure a concentrate containing as much as 45% soap can bemanufactured. It will have an acid number of about 4 to 10 which upondilution to a 1% to 2% concentration in oil will give an acid number inthe product of about 0.15 to 0.4.

Soap mam-1n producing a blended oil in one operation (production of soapin situ) by the direct neutralization method, the amount of acidcorresponding to the desired final soap content is added to thelubricating oil to be modified. A small amount of filter aid such as0.25% to 1.0% of refined diatomaceous earth (such as said "super-eel)may be added depending upon the choice of subsequent operations.Powdered calcium oxide or hydroxide (of which 90% preferably passes a200 mesh screen) together with 20% to 100% as much water based on thelime, or a slurry of the calcium hydroxide in water, is added in anamount corresponding to the chemical equivalent of the acids. The amountneutralization of the acids. This mixture is then passed through atubular heater or the like, as is commonly done .in contact claytreating of lubricating oils, although the heating and dehydration maybe done in batch. The temperature is raised tobetween about 325 F. and375 F. and the oil is discharged into a surge or flash drum where thewater is eliminated in the form of vapor. Vacuum or stripping with aninert gas may be used to aid the removal of water. The oil is thenpassed through either a centrifuge or a filter to remove undesirablematerial. In some instances it has been found possible to omitclarification of the mixture from the surge drum by reason of goodsettling of undissolved materials at that point.

While the use of lime equivalent to the acid requirements may besatisfactory, it is ordinarily preferable to use an excess of the limebetween about 10% and 100% excess, the filter aid mentioned being usedin this instance also. This filter aid, which preferably is an inertmaterial such as the purified diatomaceous earth above mentioned, shouldnot in general contain large amounts of adsorbent clay or bleaching'agent, because the highly adsorptive clays have a tendency to removethe soap and thereby decrease the eflectiveness of the product. Howevera very small amount of bleaching clay may sometimes be employed toimprove color without serious loss of soap therefrom.

Soap production by double decomposition-In addition to'the directneutralization above described, the soaps may be prepared by doubledecomposition of the water-soluble soaps in solution by means of calciumchloride or nitrate or like water-soluble calcium salts. Suchwater-soluble soaps may be sodium chloro-soaps such as above describedas being prepared from the chlorinated esters, or of course they may beprepared by direct neutralization of chloro-stearic or other indicatedacids which have been produced by direct chlorination of such acids.Sols id calcium chloride or nitrate or solutions thereof may be used.The operation consists merely in adding the calcium salt or its solutionto the soap solution and agitating to effect adequate mixture, whereuponthe soap is precipitated, ill- 10 tered, and washed at temperaturesbelow the melting or sintering point. The soap is then air dried at notover 125 1''. Vacuum drying may be used advantageously at thesetemperatures. The object of restricting the temperature is to 15 avoidsinterlng. Should it not be desired to handie the soap as a dried solidafter its precipitation by double decomposition and recovery, a portionof lubricating oil may be added before, during or after the addition ofthe water-soluble 3 calcium salt above mentioned, the temperature beingnow maintained above the melting point of the soap, for example at 180F. In this mixture the soap precipitates and is gathered into a magma orviscous mass which can be washed with hot water by decantatlon. Thisprocedure avoids filtration and air drying. After the resultant pulp iswashed until practically free from inorganic salts (e. g. calciumchloride), additional small proportions of oil may be added if desired.This pulp is then dried by heating with closed steam (such as in a steamjacketed grease kettle) to bring it to a temperature between about 300F. and 350 F. while being agitated. This operation yields a concentratewhich after 35 heating and agitation is a viscous, flowable, noncheesyfluid at ordinary temperatures. By restricting the oil content thisconcentrate may be made to contain about 45% of the soap or byincreasing the oil content it may be made to 40 contain as little soapas desired. More than about 45% soap renders the concentrate still anddimcultly flowable and therefore awkward to handle. Such concentratesare readily miscible with lubricating oil in all proportions.

BucNnmo FINAL Pnonuc'rs The blending of a soap concentrate with alubricating oil of such type as has been hereinabove indicated, may becarried out at any temperature 5 at which the components aresufficiently fluid to obtain thorough mixing, for example 120 F. to 150F. However, if dry, solid soap is used, it is desirable to heat afteradding the soap to the oil to insure complete dehydration as explained 5above. In some instances it has been found desirable to subject thefinally blended oil to a clarification treatment as by centrifuging orby 111- tering to remove any haze which might be present from a numberof sources, for example contamination from the equipment or fromreagents or from the presence of oil-insoluble soaps includingunchlorinated calcium stearate or oil-insoluble magnesium soaps. As hasbeen indicated,

the presence of magnesium may be eliminated by 35 purification of thelime before use.

Free ac'iditzg-In general the'presence of free acidity, as determined bytitration with potassium hydroxide to a phenol phthalein end point,apparently aids in obtaining suitable solutions 70 of chlorinated soapsin oil. This free acidity usually represents only a small proportionbased on the blended oil, the range usually being between about 0.0'1%and 0.2% (corresponding roughly to acid numbers of about 0.14 to 0.4, l.e,

7 mg. KOH per gram of oil). Variations on either side of this range havebeen noted in fairly stable blends, but in general the principle seemsto hold that any particular batch of soap which is prone to giveexcessive increase in viscosity, cloud or sedimentation in the blendedoil is usually im- 5 proved in its blendability by the presence-of somefree acid. Usually it is permissible and conven ient for the free acidto belong to the same class as the acids used in forming the soap.However other acids such as unchlorinated oieic acid are sometimesconveniently usable. Further- 1 more, it has been observed that simplyheating and holding a cloudy concentrate or diluted blend at an elevatedtemperature, for a period of time, for example at about 325 F. for onehour, improves the compatibility of the soap in the oil upon cooling,and subsequent titrations usually indicate an increase in acid numberunder these conditions without the necessity for any other adjustment orexercise of care to insure an acid content. It is preferable, however,to avoid excessively high free acid contents because of the possibilityof encountering corrosion with certain engine materials such as bronzehearings or bushings.

Controlling acidity re-neutralization.0rganic bases such astriethanolamine can be employed in some cases as an aid in controllingacidity. This use will be understood from the following example. A batchof soap concentrate containing approximately 20% calciumdichlorostearate was found to give a blended oil of 0.7 acid number whendiluted to a soap content of 1.3%. This soap concentrate had beenproduced, by heating a mixture of mineral oil, chlcro-acids (20%chlorine content) and a slight excess of lime to 325 F. with agitationand holding at 325. F. to 340 F. until dehydration was complete. Thedehydrated concentrate containing 0.5% refined diatomaceous earthSuper-eel) 49 was filtered giving the 20% concentrate referred to above.For the purpose of reducing the acid number obtained on blending, aportion of the concentrate was retreated with lime and said earth and adefinite improvement was obtained as shown by an acid number of 0.4 onblending to 1.3% soap content. However, to obtain a still furtherreduction in acid number, another portion of the concentrate wasretreated with the same amount of lime and earth as used in the lastoperation but 0.5% triethanolamine was added when the concentrate was at250 F. during the heating up to 325 F. After complete dehydration, themixture was filtered, giving a product which was fluid on cooling andyet which gave an acid number of only 0.2 on biending to 1.3% soapcontent.

In other instances small amounts of concentrated aqueous solutions ofsodium hydroxide and potassium hydroxide have been used alone and inconjunction with additional lime in the reneutralizatlon to obtainunusually low acid numbers of the order of 0.05 on the finished enginelubricant containing 1.3% total soaps. An oil reneutralized withconcentrated KOH, for example, was found to be especially non-corrosiveto bronze wrist pin and babbit crank shaft bearings. The use ofalcoholic potassium hydroxide or sodium or potassium alcoholates suchaspotassium methylate and ethylate is practical and has the advantage ofreducing foaming difficulties attendant upon the last stages ofdehydration as explained elsewhere. In carrying out the reneutralizationwith solution of alkali hydroxide, it is often more feasible, espcciallyin batch operations, to cool the lime-neutralized mix to below theboiling point of water, or alcohol as the case may be, before adding thesolution of alkali. Also the unreacted lime and other solids from theprevious neutralization may or may not have been filtered off before thealkali for the re-neutralization is added. If the alkali is added afterfiltering off unreacted lime, etc., it is advisable to add an additionalamount of super-cel, reheat and refilter.

Where the acid number in a soap-oil concentrate containing considerablesoap, e. g. 40%, is brought below about 1.5, the tendency is for theconcentrate to become cheesy. Here the filtering may be eft until theblending operation when the final blend is heated to effect finaldehydration and is finally filtered to remove unreactcd solids.

Thus, the control of acidity by reducing the acid number, where toohigh, by re-neutralization as above indicated, may be accomplished byretreatment with additional quantities of the same base as originallyemployed such as the calcium hydroxide, or by treatment with other basessuch as NaOH or KOH with or without clay or the earth above mentioned,or ammonium carbonate, or organic bases such as the mentionedtriethanolamine, or monoethanolamine, triethylene tetramine,triamylamine, morphollne and the like. Where the base used forreneutralization is different from that originally used, soap mixturesare of course obtained. Very desirable results have been obtained withthe mixture heretofore mentioned containing 1% calcium chlorostearatesand 0.3% triethanolamine chlorostearates, which was produced through theabove described re-neutralization. A very desirable and apparentlypreferential maximum acid number of about 0.2 may be obtained-by suchprocedures as well as the above indicated unusually low acid number ofonly 0.05. As in the original neutralization, the use of a small amountof water in the re-neutralization is helpful.

Paonuors A typical oil produced for Diesel engine lubrication consistedof 1.3% calcium chlorostearates and 98.7% Western type naphthenic baseoil of Acid number 0.03 Carbon residue" 0.10

The calcium chlorostearates contained 18.5% chlorine based on the acidwhich was representative of dichlorostearate predominantly. Theresultant blend possessed the following characteristics:

Gravity 20.6 A. P. I.

Viscosity 550 seconds at F.; 55 sec- 1 onds at 210 F.

Pour point Flows at --10- F.

Flash C. O. C--. 380 F.

Ash 0.13

Color 4 N. P. A.

Acid number 0.18 Carbon residue 0.32

In addition to chlorinated calcium stearates as above indicated othersuitable oil-soluble soaps may be employed such as aluminumdichloroleate and aluminum dichlorostearate. However, I have found thatfor most purposes magnesium soaps of such chlorinated acids are notdesirable because of their strong tendency to cloud. In addition to theordinaryelimination'of magnesium, it is also desirable'to avoid a verylarge proportion of unohlorinated stearic acid for the reason thatneither the stearic acid itself nor calcium stearate therefrom issufficiently soluble in or compatible with the 011. However, as statedabove, the chloro-soaps have a marked solubilizing action onunchlorinated soaps and it therefore usually is unecessary to eliminateall unchlorinated acids. The exact proportion of unchlorinated acids orsoaps therefrom that can be tolerated depends on both the acid and theoil being treated. In general, the more naph thenic the oil, the moreunchlorinated acid can be tolerated, whereas with a highly parafflnicoil, it has been found preferable in the case of stearic acids, topurify the chloro-acids to a point of practically complete eliminationof unchlorinated stearic acid, as by refining the chloro-acids by coldpressing to a pour point of 25 F.

Also, certain soap mixtures are very desirable, especially a mixture ofthe indicated calcium chlorostearates and calcium phenyl stearate inproportions ranging for example from one part of one of the soaps tothree parts of the other of the. two soaps, the soap being used in thepercentage range heretofore indicated between about 1% and about 2%combined soap in the average Diesel engine lubricating oil. Also, theabove indicated mixtures obtained by re-neutralization such as calciumchlorostearates with smaller proportions of triethanolamine chlorostearates (such as dichlorostearates) and similar soaps are valuable. Myinvention includes also such soap mixtures in oil regardless of themethod of production of the soaps.

' Other soaps.Again, soaps of other chlorinated fatty acids having aminimum of about 14 carbons to insure a sufliciently high molecularweight and boiling point may be employed. Corresponding soaps ofchlorinated synthetic petroleum acids likewise may be employed. Theseacids themselves are well known on the market, and are frequentlyproduced by oxidation, catalytioally and otherwise, of paraflinicpetroleum products, oxidation being a convenient means for the formationof the acids. These acids are recovered by converting into water-solublealkali soaps and subsequently cracking out by the use of strong mineralacids to yield the purified acids. These procedures are generally wellunderstood and need not be here described. These acids may be more orless readily chlorinated or otherwise halogenated by passage of thehalogen gas through the liquid acids to effect the desired substitutionand/or addition, followed by removal of HCl and ex cess Ch. The soaps ofsuch halogenated acids are then readily formed by reaction with suitablemetal salts, hydroxides or oxides in the same way that fatty acid soapsare formed. Usually the synthetic petroleum acids recovered as indicatedabove contain also certain other types of compounds such as ketones andesters, and the presence of these other types of molecular structureshasbeen found to be beneflcial generally speaking rather thandetrimental. In fact experience has shown that the 75 presence, as such,of the ester-'ketonic products obtained during the oxidation ofparaiiinic hydrocarbons or produced by esteriilcation of syn-' theticpetroleum acids with methyl or ethyl alcohol is often desirable from thestandpoint of oiliness, and maintaining a tightly adsorbed layer ofnon-corrosive material which protects against corrosion of the metalfrom water, combustion products, decomposition products and the like.

With respect to thesynthetic petroleum acids, paraflin acids and thelike such as produced by oxidation as herein mentioned, as distinguishedfrom naphthenic acids, attention is called to the fact that these acidsare of different character from naphthenic acids and present a vastlygreater degree of oiliness properties than do the naphthenic acids andare in most instances to be preferred to naphthenic acids orany othernaturally occurring petroleum acid such as obtained from petroleumdistillates. The synthetic petroleum and paraflln acids mentioned may beproduced by oxidation as well understood in the art or otherwise. Theesters of the synthetic petroleum acids are also valuable adjuncts tooil-soluble soaps as explained above. For exam ple the performance of anoil containing 1.25% of calcium dlchlorostearate was improved by theaddition of 1% of methylated ester obtained from oxidized parafiln wax.

Inaddition to the indicated metal soaps of various halogenated fattyacids such as oleic, linoleic, stearic, palmitic and the like, and theindicated soaps of halogenated naphthenic acids and halogenatedsynthetic petroleum acid, I may also use corresponding oil-solublesulfurized or phosphorous-bearing soaps of such acids of sufficientlyhigh molecular weight as herein indicated. Also, I contemplate the useof special soaps, such as a lead soap of highly chlorinated organicacids, particularly naphthenic acids, as components in extreme pressuregear oils and the like. Thus, the oil-soluble lead soaps of thechlorinated or otherwise halogenated naphthenic acids, correspondingsulfurized acids, and halogenated and sulfurized lard oils and fattyacids, and the like are included. These acids should contain at leastten carbon atoms per molecule. Such lead soaps may be used alone or inconjunction with other halogenated or sulfurized soaps herein disclosedor with oiliness agents of the oxygenated type such as esters, ketone,etc., produced from oxidized petroleum fractions.

Organic bases.Similarly, I may use organic bases in preparing soaps forthe use of the present invention. Such bases are represented bytriethanolamine, quinoline bases, nitrogen bases from petroleum and thelike. Where the triethanolamine soap is to be used as one of thecomponents of a two-component additive material, the acids would notgenerally contain an oiliness element such as chlorine, sulfur or thelike. Such acids may be naphthenic acids, fatty acids containing aminimum of about 14 carbon atoms, synthetic petroleum acids as fromoxidation of paraflin waxes and refined petroleum oils and all othertypes of acids herein mentioned. When the organic base soap, such as atriethanolamine soap, is to be used as a single component additive,thenthe acid radical will contain the oiliness agent such as chlorine,sulfur, phosphorus or other suitable substituent. Soaps of thischaracter will be used in percentages similar to those employed withother soaps,

or in smaller percentages when used in conjunction with otheroil-soluble metal soaps.-

Soaps in qeneral.In all aspects of the present invention, it will ofcourse be obvious that in the case of chlorinated or suifurized orsimilar materials either the acids employed may first be chlorinated orotherwise treated, or the soaps after their formation may be sochlorinated, sulfurized, or otherwise modified, and the materialsproduced by both methods are intended to be included when acids andsoaps are mentioned herein. V

Soaps of the indicated nature when added to lubricating oils are stablein use, and when empioyed'in the indicated proportions do notappreciablyaflect" the fluidity of the oils for lubrication purposes.The amount of soap to be added to the oil, as is evident from the abovedisclosure, is that quantity necessary to effectively avoid substantialdeposit of gummy, resinous and varnish-like materials whereby toovercome ring and valve sticking in internal combustion enginesespecially engines of the Diesel type, and also in high output aviationengines. At the same time tendencies in fuel ,used in the engines todeposit similar or other gummy resinous varnish-like constituents whichtend to cause ring valve sticking, are likewise overcome by the use ofsuch amount of the indicated type of soap. As has been indicated, thisamount is ordinarily in the order of about 1%. Besides an ordinary rangebetween about 1% and 2% as previously indicated, there may be instanceswhere as little as 0.25% may be used, and on the other hand, largeramounts extending up to possibly as high as 3% may be desirable undersome conditions. In other words, varying conditions can possibly requirewider ranges.

Mum-component material8.-According to another form of the invention, Ihave found it practicable to use a two-component additive material, oneof which is a non-halogenated or non-sul- Iurized soap for the purposeof prevention of deposition of gums and resins and the like, and theother of which is an oiliness constituent which imparts high loadcarrying capacity. Whereas, in the case of a single component material,calcium dlchlorostearate for example, both the oiliness element and theelement for overcoming deposition of gums and resins are contained inone compound, in this modification of the invention the soap whichlargely overcomes deposition of gums and resins does not containcombined therein an agent for improving oiliness and film strength, suchas sulfur, a halogen, phosphorous, or the like, but the soap is employedin conjunc tion with a second component which is halogenated, sulfurizedor phosphorized of which methyl dlchlorostearate is a good example, suchsecond agent imparting the desired increased load carrying capacity. Forexample, I may employ approximately 1% to 1.5% of an oil-soluble calciumsoap of palm oil acids, oleic acid, phenylstearic acid or the like, orother disclosed acid, together with about 0.5% to 1.0% oi methyldichlorostearate to increase film strength and load carrying capacity.Other oiliness or film strength agents of this general type may besubstituted such as those produced from ethyl, amyl or other alcoholsand oleic, palmitic, phenyl stearic and other acids, the agentcontaining chlorine. In addition to halogenated ester types, I mayemploy other types of oiliness or film strength agents, such aschlorinated naphthalene, chlorinated diphenyl oxide, chlorinatedparafiin, sul- Iurized lard oil, chlorinated or sulim'ized jojoba oil(which is a vegetable oil which readily takes up either small quantitiesof sulfur or large quantities as high as 25% sulfur, without turningblack), sulfurized fatty acid esters, tricresyl phosphate and kindredphosphorous compounds; and oxygenated compounds of the ester, ketonic oraldehydic types such as those obtained from oxidized paraflinicpetroleum iractions,'as such or when chlorinated. In this manner theoiliness element such as chlorine, sulfur, phosphorous, or oxygen, isobtained through the medium of an agent other than the soap.

Also, in addition to the type of soaps containing a film strength agent,such as calclum dichlorostearate or triethanolamine dichlorostearate (ora mixture), I may use therewith a second material not a soap such asthose non-soap materials above mentioned for imparting oiliness 29characteristics, but more especially materials of which esters of theabove mentioned synthetic petroleum acids obtained by oxidation of par--aiilnic materials are representative; for example the methyl esters ofsuch synthetic petroleum acids in particular, and also ethyl and amylesters and the like. Such second material may or may not be chlorinated.In such blends only the soap needs to-be confined within the indicatedlimits of about 1% to 2%, but the other 30 additive would ordinarily notexceed an additional 1% or thereabouts. Also, my invention includes theuse or these chlorinated esters of, synthetic petroleum acids obtainedby oxidation, as oiliness agents in lubricating oil in amounts betweenlimits of about 0.25% to 3% and with or without soaps or other types ofaddition agents.

Mineral lubricating oils to be used in. practicing this invention arenormally of the ordinary S. A. E. grades employed for enginelubrication, and more particularly the S. A. E. 20, 30 and 40 grades,but the invention is not necessarily limited thereto.

Ordinarily, and exceptwhere otherwise indicated, the termdichlorostearate or dichlorostearic acid or equivalent term is intendedto include also the soap or acid obtained by satura-- tion oi. oleicacid with chlorine, the two products appearing to be equally valuable,the only dif- 50 ference being that the chlorines appear to enter atdifferent places in the chain.

In stating that the indicated proportions of soaps employed inlubricating oils (1. e. in the order of about 1% to 2%) do notappreciably 55 affect the fluidity of the oils, this refers to aviscosity increase of less than one S. A. E. grade or an increase of notover about four seconds flaybolt Universal at 210 F.

When the term complete dehydration is used herein it means thatdegreewhich renders the concentrate flowable as herein described andperi and being free from substantial increase m cosity over the baseoil.

haps reduces the water content to as little as 0.25% or less.

7 Where the term "calcium oxide is used in re- 5 ferring to the basematerial employed :for soap production, it is intended to include boththe anhydrous calcium oxide as such or the hydrated calcium oxide(hydroxide), except where otherwise indicated.

70 While the invention has been indicated as particularly applicable tomineral lubricating oils, it

may also be extended to fatty lubricating oils and present invention,and that they are not to be taken as limiting beyond the requirements ofthe prior art and as indicated by the appended claims.

I claim:

1. A lubricant comprising at least about 97% or mineral lubricating oiland between about 1% and 2% of oil-soluble soap constituent of organicacid containing ten or more carbon atoms and including afllm-strengthincreasing constituent in a class consisting of halogens,sulphur and phosphorous, said soap not materially increasing theviscosity 9! the oil and possessing detergent properties for gums andthe like formed in internal combustion engines, the soap beingsubstantially anhydrous.

2. A Diesel engine lubricating oil comprising a mineral lubricating oiland oil-soluble metal soap constituent of organic acid containing atleast ten carbon atoms and including a halogen film-strength improvingconstituent, the additive soap material being in the order of 1% to 2%and suflicient only approximately to overcome ring sticking andformation of gummy and varnish-like bodies but insumcient to materiallyincrease the viscosity of the mineral lubricating oil, the soap beingsubstantially anhydrous and the oil containing a small proportion 01' acommon solvent for the soap and oil.

3. A Diesel engine lubricating oil comprising mineral lubricating oilcontaining between about 1% and about 2% 01 oil-soluble metal soap ofchlorinated fatty acid having a chlorine content between about and beingsubstantially anhydrous and containing a small proportion ofunsaponifled fatty acid, whereby the soap is freely dissolved in the oiland without material increase in viscosity.

4. A Diesel engine oil according to claim 3 wherein the chlorine contentcorresponds generally to a dichloro soap.

5. A severe service engine lubricating 011 comprising a minerallubricating 011 containing between about 0.8% and about 2% oi calciumsoap of chlorinated iatty acid having ten or more carbon atoms to themolecule and having a chlorine'content between about 15% and 25%, theproduct being approximately anhydrous and containing a small proportion01' tree saponiflable organic acid as a solubilizing agent and be-, ingtree from substantial increase in viscosity over the base oil.

6. A lubricating 011 comprising mineral lubricating oil and betweenabout 0.8% and about 2% of oil-soluble soap of fatty acid containing atleast ten carbon atoms and having a chlorine content between about 17%and 21% based on the acid, the product being approximately anhy drousand containing a small proportion of free saponiflable organic acid as asolubilizing agent 'I. A Diesel engine lubricating 011 comprisingmineral lubricating oil and between about 1% andabout 2% of calcium soapor chlorinated organic acid containing ten or more carbon atoms,- thesoap possessing a chlorine content representative o! a predominatingproportion oi! calcium di-chloro soaps, the product being approximatelyanhydrous and containing a small proportion of free saponiiiable organicacid as a solubilizing agent and being free from substantial increase inviscosity over the base oil.

8. A normally flowable substantially anhydrous lubricant comprising asprinciple ingredients mineral lubricating oil and at least about 0.8% ofoil-soluble soap of organic acid of the class consisting of halogenated,sulphurized and phosphorized synthetic petroleum and fatty acidscontaining ten or more carbon atoms.

9. A Diesel engine lubricating oil comprising mineral lubricating oilhaving haphthenic base characteristics containing a small quantity inthe order of about 1% to 2% of substantially anhydrous oil-soluble metalsoap of chlorinated organic acids containing ten or more carbon atomsand a smaller proportion of unsaponiiled organic acid to insure solutionof the soap in the oil. a

10. A Diesel engine lubricating oil containing a small quantity betweenabout 0.8% and 2% of. substantially anhydrous calcium chlorostearatecontaining chlorine corresponding approximately to thedichloro-stearate, without substantial increase in the viscosity of theoriginal lubricating oil.

11. A Diesel engine lubricating oil comprising a naphthenio base minerallubricating oil and between about 0.8% and 2% oil-soluble substantiallyanhydrous calcium chloro-stearates. the oil being freely liquid withoutsubstantial increase in viscosity over the original lubricating oil.

12. A mineral lubricating oil especially adapted for use in severeservice internal combustion engines comprising a mixture freely liquidat normal temperatures of a naphthenic base mineral lubricating oil andbetween about 1% and 3% of an oil-soluble calcium soap of a chlorinatedorganic acid containing at least ten carbon atoms, the soaps containingbetween about 10% and about 40% of chlorine basedon the acid,the-resultant product being substantially anhydrous and having thecharacter of overcoming accumulation of resin and varnishlike materialsupon piston rings in internal combustion engines without appreciableincrease in the viscosity of the original base oil.

.13. An oil according to claim 12 having free small organic acid contentto insure solution of the soap in the oil and freedom from substantialviscosity increase.

14. A lubricant comprising mineral lubricating oil and a substantiallyanhydrous mixture of calcium phenyl-stearate and calcium chlorostearatescorresponding generally with calcium dichiorostearate.

15. A lubricating oil containing between about l%-and 2% of a mixture 0!calcium chlorostearates containing between about 15% and 25% chlorine,and triethanolamine chlorostearate.

16. A lubricating oil containing between about 1% and 2% of a mixture ofcalcium chlorostearates containing between about 15% and 25% chlorine,and potassium chlorostearate.

1']. A substantially anhydrous lubricant comprising mineral lubricatingoil, oil-soluble metal soap of'chlorinated fatty acid having at leastten carbon atoms, and lead soap of chlorinated naphthenic acid, thecombined soap content being at least about 1% based on the mineral oil.

18. A substantially anhydrous lubricating oil comprising minerallubricating oil, oil-soluble lead soap of chlorinated organic acid ofthe class consisting of synthetic petroleum acids, naphthenic acids andfatty acids containing at least ten carbon atoms in the molecule, andoilsoluble soap. other than said lead soap, of chlorinated organic acidfrom the class consisting of synthetic petroleum acids and fatty acidscontaining at least ten carbon atoms in the molecule, the combined soapcontent amounting to at least about 1% of the oil.

19. A substantially anhydrous Diesel ensin lubricating 011 comprising asprimary constituents a naphthenic base mineral lubricating oil andbetween about 1% to 2% of oil-soluble metal can of chlorinated organicacid from a class consisting oi synthetic petroleum acids containing tenor more carbon atoms to the molecule and fatty acids containing at leastten carbon atoms to the molecule.

20. A lubricating oil according to claim 32 containing between about0.8% and about 2% of calcium soap of the acid.

21. A substantially anhydrous lubricating oil for heavy service internalcombustion engines comprising a mineral lubricating oil having goodsolvent power for soaps and containing between about 1% and about 2%combined oi oil-insoluble soap of organic acid containing 'at least tencarbon atoms and oil-soluble soap of organic acid containing at leastten carbon atoms and also containing chlorine in sufllcient quantity torender the soap oil-soluble, said oil-soluble soap being in excess ofthe oil-insoluble soap and exerting a solubilizing action upon saidoil-insoluble soap.

22. A viscous concentrate for the addition to lubricating oilscomprising a substantially anhydrous mixture of mineral lubricating oiland between about 10% to 45% of oil-soluble soap of chlorinated fattyacid containing at leastten carbon atoms, the soap containing betweenabout 10% and 40% of chlorine based on the acid. the concentrate beingflowable at normal room temperature. I

23. A method for preparing lubricating concentrates comprising minerallubricating oil and oil-soluble soap wherein the soap contains betweenabout 10% and 40% chlorine, said method comprising adding chlorinatedfatty acids coutaining at least 10 carbon atoms to mineral lubricatingoil, adding a base to the mixture, heating and agitating to efiectneutralization of the mixture with a residual acid number in excess of0.2, filtering, and re-neutralizing the mixture with base to reduce theacid number to a maxi-- mum less than approximately 0.2, and filtering.

24. A method according to claim 28 wherein the first base is calciumoxide and the second base is an ethanolamine.

25. A method according to claim 27 wherein the first base is calciumoxide and the second base is potassium hydroxide or alcoholate.

26. A method of preparing lubricating oils comprising chlorinatingnormally solidfatty acids to effect a mixture of relatively heavilychlorinated fatty acids and lightly chlorinated or unchlorinatedmaterials, chilling the mixture to precipitate unchlorinated and lightlychlorinated materials, cold pressing the chilled mixture to recoverliquid more heavily chlorinated fatty acids, saponifying said normallyliquid chlorinated fatty acids to yield oil-soluble soaps, effectingsolution of the resultant soaps in mineral lubricating oils andeffecting dehydration of the mass. 1

27. A method for the preparation of lubricating oils comprisingchlorinating material containing a stearic acid radical to producechlorinated stearic acids corresponding in chlorine content todichlorostearic acid, recovering such stearic acids, effecting solutionof such stearic acids in lubricating oil, adding calcium oxide,

heating to effect reaction to produce calcium chloro-stearates andsubstantially dehydrate the solution, and filtering out undissolvedmaterials.-

28. A lubricating oil for internal combustion engines comprising minerallubricating oil containing between about 1% and 2% calcium soap ofchlorinated fatty acids containing at least ten carbon atoms to themolecule and chlorine representative of a preponderance of dichioroacids, the composition being substantially free from water andwater-soluble salts, and containing a small proportion of freesaponiilable organic acid as a solubilizing agent.

29. A dehydrated soap concentrate comprising mineral lubricating 011containing oil-soluble calcium soap of chlorinated fatty acids having atleast ten carbon atoms to the molecule and containing chlorinerepresentative of a preponderance of dichloro acids, the compositionbeing substantially free from calcium chloride.

30. A method for producing lubricating oils which comprises forming acalcium soap of chlorinated fatty acids containing at least ten carbonatoms to the molecule, supplying a proportion of lubricating oil to thesoap, washing the soap-oil mixture until the mixture is substantiallyfree from metal chloride, and dehydrating the mixture.

31. A method for the production of lubricating oil concentratescomprising reacting chlorinated fatty acids containing at least tencarbon atoms to the molecule vwith a calcium compound to produce calciumsoap in the presence of a proportion of mineral lubricating oil,filtering the soap-oil mixture, washing to remove water-solublematerials including calcium chloride, dehydrating the resultant soap-oilconcentrate, and combining the washed, dehydrated concentratesubstantially free from calcium chloride with additional minerallubricating oil.

32. A lubricating oil which is freely liquid at ordinary temperaturescomprising a mineral lubricating oil containing more than about 0.8% ofan oil-soluble metal soap of a saponiilable organic acid containing atleast 10 carbon atoms to-the molecule in chemical combination with afllm strength increasing agent .of the class of the halogens, sulfur andphosphorous and containing sufficient unsaponiiied organic -acid toobtain free dispersion of the soap and render the soap mixture freelyfluid, the oil product being substantially anhydrous and possessingsubstantially the same viscosity as the original mineral lubricatingoil.

33. An oil according to claim 32 wherein the soap is an alkaline earthmetal soap containing chlorine corresponding roughly to the dichiorosoap.

34. An oil according to claim 32 wherein the soap is a calcium chlorofatty acid soap containing chlorine corresponding roughly to thedichloro soap.

35. A lubricating oil which is normally freely liquid comprising minerallubricating oil and at least about one percent of calcium chloro fattyacid soap containing chlorine corresponding generally with the dichlorosoap, the soap being almost completely anhydrous and freely soluble inthe oil without imparting substantial viscosity increase or grease-likecharacteristics to the original lubricating oil.

36. A lubricating oil according to claim 35 wherein the mineral oil is anaphthenic base oil.

37. A lubricating oil according to claim 35 wherein the product containsin the order of 0.07% to 0.2% of unsaponifled organic acid.

ULRIC B. BRAY.

Patent No. Li 2 5 3 CERTIFICATE OF CORRECTION.

' December 1 191m.

ULRIC B. BRAY.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as followe Page 9,second column, line '27, after "ring" insert "and"; page 11, secondcolumn, line 55, claim 25, for the claim referen'ce numeral "27" read--25-; and that the said Letters Patent should be read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 1st day of April, A. D. 191d. 7

I Henry Van Arsdale, (Seal)- 4 Acting Commissioner of Patents.

